I am a middle school Language Arts teacher who teaches high-level eighth grade students (in other words, VERY smart, motivated, and voracious readers). I suspect that when Sharon Draper was a teacher, she taught some lower-level students because this book seems to be clearly geared towards those students.
The author can write, but I feel this particular work is not challenging, as everything seems to be over-explained, and, though heartfelt, relatively two-dimensional. When each major character harbors a Secret, and through a series of incidents where all the Secrets are revealed, these Secrets don't meet up with deeper intellectual meaning. In short, I find both plot and character exist in the world of Afterschool Specials -- simple, over-explained and highly coincidental.
Many kids will enjoy this book, but mine will not.